Telephony.



No. 783,419. PATENTED FEB. 28, 1905.

E. A. BUELL.

TELEPHONY.

APPLICATION FILED MAY 1904.

zveizzar, MW (L M UNiTEn STATES Patentedfiebruary 28, 1905.

PATENT Orrica,

EDWVARD A. BUELL, OF DEKALB, ILLINOIS, ASSIGNOR TO SELECTIVE SIGNAL & TELEPHONE MANUFACTURING, CO, OF SYOAMORE, ILLI- NOIS, A CORPORATION OF ILLINOIS.

TELEPHONY.

SPECIFICATION forming part of Letters Patent No. 783,419, dated February 28,1905.

Application filed May 2, I904. Serial No. 205,876.

1'0 all w/wm it may concern:

Be it known that I, EDWARD A. BUELL, a subject of the King of Great Britain and Ireland, residing at the city of Dekalb, in the county of Dekalb and State of Illinois, have invented certain new and useful Improvements in T elephony,of which the following is a speciiication, reference being had therein to the accompanying drawing.

My invention relates to telephony, and has for its object the provision of an improved telephone system whereby a single telephoneline may be equipped with a plurality of subscribers stations between any two of which conversation may be carried on without interference from any of the remaining subscribers stations or between any one of which and a substation of a totally-distinct line conversation may be held without interference from any of the subscribers stations elsewhere connected with the telephone-circuit.

, By means of my invention a party-line may, with its apparatus, retain the functions that make party-lines so serviceable, chief among which is the ability of the subscribers to sig nal each other and get into communication with each other without the aid of the exchange operator. Where it is desired to have the conversation between two subscribers of a party-line or a single subscriber of the partyline and the subscriber of another line perfectly secret so far as remaining subscribers are concerned and where it is desired to prevent other subscribers from signaling upon the line during such secret connection, I provide an improved secrecy and cut-off switching mechanism operated directly at the substations by electromagnetic mechanism by the aid of switching apparatus at the exchange, whereby the telephonic apparatus and desirably also the signaling apparatus is electrically disconnected at all stations except at those stations between which the conversation is to be conducted. I

I am aware that it has been the practice hitherto to effect a joint control of the telephone and signal receivers of a party-line by telephone switch-hooks and electromagnetic apparatus at the substations, said apparatus being controlled by a switching apparatus at the exchange, said electromagnetic apparatus being set at stations to be locked out, so that they will not permit the closure of the telephone-receiver circuits or to place switching apparatus operable by the switch-hooks in such a condition of use with respect to the switch-hooks that when said hooks are relieved of the receivers the switching apparatus immediately controlled thereby will not close the telephone-receiver circuits. In the apparatus of my invention the control of the telephonereceiver circuits and preferably also the signal-receiving circuits is effected by electromagnetic switching apparatus at the substations physically or mechanically independent of the switch-hooks, so that said electromagnetic switching apparatus may freely and fully control the connections through the said receivers without being liable to impairment by the violent operation ofthe switch-hooks and being capable of being located in any portion of the subscribers telephone outfits. The apparatus of my invention also enables me to equip the same in complete sets having a physical relation entirely independent of installed telephonic outfits, whereby existing telephonelines, where the use of my invention is rendered desirable, may be equipped therewith without in the slightest degree impairing the original installation or modifying the mechanical structure of the originally-installed apparatus.

Obviously as the insertion of my improved mechanism in existing branches from a partyline does not interfere with originally-installed apparatus my invention permits any subscriber to use an idle party telephone-line for the purpose of signaling any other subscriber: upon the party-line, so that said partyline is capable of its original use in that any subscriber may call any other subscriber and carry on a conversation without the aid of the exchange, which is a feature I believe to be new with me. It will be further seen that the apparatus at each of the substations is always within the control of the operator, so that either or both of these subscribers may be dis connected for any purpose, as to enable one or the other to be brought into communica tion with a third subscriber or to enable two new subscribers to be placed into communication with each other by the party-line to the exclusion of the first two.

I will explain my invention more fully by reference to the accompanying drawing, illustrating one embodiment thereof, the drawing showing a party telephone-line and so much of the apparatus at an exchange as is neces sary to an understanding of my invention.

At the exchange I have indicated line-jacks 1 and 2 of normally independent telephonelines, there being a cord connecting apparatus for uniting independent telephone-lines in conversation, such cord connecting apparatus including an answering-plug 3 and a connecting-plug 4, which cord-circuit has the usual associate apparatus, including, among other things, (not shown,) an operators telephone outfit 5, an operators ringing-generator 6, a listening-key 7, and a ringing-keyS, there being provided a common actuating-lever 9, whereby the springs of the listening-key may be pressed against the operators telephoneterminals and whereby the springs of the ringing-key may be removed from their normal contacts and brought into engagement with the alternate contacts, which constitute the ultimate terminals of the"ringing-generator 6. Both of the alternate contacts of the ringingkey 8 are thus used when the bells to be rung by the generator are in metallic connection only with the telephone-lines.

In my present system I have indicated grounded signal receivers or bells 10 at the substations which are connected with the sleeve side of the party telephoneline 11, and I hence preferably provide a supplemental key 12, which is operated to limit the current emanating from the generator to the sleeve side of the telephone-line, the circuit being completed by way of the grounded alternate contact of the key 12 and the grounded hell. 1, however, do not wish to be limited in all embodiments of my invention to the use of the grounded bells. l have indicated upon the party telephone-line three stations A, B, and C, though the number of stations connected with the line may be varied. The various stations are connected in multiple or bridge between the sides of the party-line, station'Abeingincluded in such a bridge-path 131 1, while station B has a bridge-path 15 15 16 16, While stationC has a bridge-path 17 18. I preferthe bridge arrangement, as the element of impedance is so largely removed, though I do not wish to be limited to such an arrangement. The appara tus at station B is illustrated in detail. The apparatus of the other stations is preferably similar thereto. At station B, I have-illustrated as one type of substation outfit a gravity telephone switch-hook 19, a telephone-receiver 20, to be and to cut out the telephone receiver and transmitter. I have indicated the Well-known magneto-generator at the substation B; but I do not wish to be limited to the use of mag neto-generators at subscribers stations. The magneto-generator 22 when operated serves to release the shutter of the line-indicator 23, which in this particular instance is grounded, and is normally in connection with the sleeve side of the party-line and the generator by way of the long spring of the line-jack 2 and the contact engaging said spring when the jack is free of a plug. In order that the current from the generator 22 may be sent in sufficient volume over the line to operate the line-indicator, the bell 10 is preferably made of very high resistance-for example, one thousand ohmsvvhich, however, is not too great to permit a fraction of the current to be diverted from the circuit containing the line-indicator through the bell to have the same operated at'the calling-station, said bell being in shunt relation with the generator. Either or both of the branches 15 15 and 16 16 may be subject to the electrical control had by the device of my invention. I have shown the side 15 to depend for its continuity upon a movable circuit-changing wheel 24, desirably in the form of a ratchet-wheel, said ratchet-wheel carrying or operating a contact element mechanically subdivided into two parts 25 and 26, insulated therefrom. these parts being desirably constructed in two mechanically-separated but electricallyeonnected elements which preferably are in the form of teeth conforming in character to the balance of the teeth of said ratchet-wheel, though I do not wish to be limited to a contact element of this form. WVhen the ratchetwheel is in its initial or normal position, the element 25 is in electrical connection with a dog or rider 27, which in turn is connected with the conductor portion 15, said conductor 15 being connected with the switch-hook and also connected with the contact elements 25 and 26, as indicated. The teeth or elements 25 and 26 are separated by a varying number of teeth at the different stations. The tooth 25 at each station is what might be termed the normal orizero contact'element. The normal or zero tooth 25' at each station is that tooth or contact element which is always directly engaged by the dog 27 at all of the stations when the lineis idle, which engagement is to be maintained when the line is to be used as an ordinary party-line. The tooth or element 26 may be termed the alternate contact element and is that tooth which is directly engaged with the dog 27 at any selected station when secrecy is desired and where selected signaling is to be practiced.

In placing two subscribers on the same line in secret connection the operator intermittently actuates the electromagnetic apparatus, to be hereinafter described; for the purpose of shifting the circuit-changing wheel 24 until the proper teeth 26 (which as hitherto set forth are located differing distances away from the teeth 25, according to the different stations) are brought into direct engagement with the dogs 27 at the stations between which the secret connection is to be established. For example, station A indicates one station upon the line, station B may indicate the next, and station (l the next. There may be other stations upon the line. It will be assumed that station A is No. 2, station B No. 3, and C No. 4, it being assumed that station 1 and the other stations are not shown. At station A the teeth 25 and 26 have a single tooth intervening, at station 13 the teeth 25 and 26 have two teeth intervening, and at station C the teeth 25 and 26 have three teeth intervening. To connect station B with station (1, for example, the operator shifts the circuitchanger 24 three steps and then locks the same by mechanism to be set forth and shifts the circuit-changing wheel 24 at station C another step, the said latter circuit-changer having previously been operated three steps in setting the apparatus at station E. It will be apparent to those skilled in the art that at all other stations the dogs27 are in connection with those portions of the circuit-changing wheels 24 that are electrically disconnected from the teeth 25 and 26, thereby separating the conductor portions 15 15. In addition to opening one side of each line leading from the party-line to the unselected stations I prefer to establish at such unselected stations short circuits across the conductors leading to the telephone switch-hooks and the telephone-receivers, which result may be accomplished by connecting the wheels 24 with the sides that are companion to the interrupted sides of the branches leading from the unselected stations to the party-line, so that when the dogs 27 rest upon the wheels 24 short circuits are established, as will be apparent by particular reference to the apparatus at station B, if it be understood that the dog 27 is in direct engagement with the body of the wheel 24. Thus both terminals of the telephone-receivers are operatively disconnected from the line. The conductor portion 16 is shown connected with a wheel 24 for the purpose stated.

Having deseribed the circuit-changing apparatus employed for governing the associa tion of the subscribers stations with the partyline, 1 will now describe the electromagnetic mechanism that is employed for effecting the operation of the said circuit-changers and will thereafter describe the switching apparatus at the exchange that is employed for opcrating the electromagnetic mechanism.

The wheels 24 are provided with coil-springs 28, by which when released by my magnetic actuating mechanism theyare restored to initial positions, where the contacts 25 engage the dogs or riders 27, the wheel 24 at'station B having thereon an arm 29 engaging a stop 30 to limit the return of the wheel. The wheel is moved against the force of this spring by means of a polarized electromagnet 31, included in parallel to the switch-hook 19 and telephone-receiver 20, this electromagnet actuating an armature 32 and moving a lever 33, insulated from the armature, each movement of the lever toward the magnet effecting a movement of the wheel 24 against the force of the spring 28, the dog 34 serving to prevent the wheel from returning. The locking is accomplished by a polarized electromagnet'35, Whose armature actuates a catch 36, normally out of the path of the nose upon the arm 29 and thrust into the path of this nose when the Wheel 24 is to be locked in a selected position, so that the operation of another wheel atanother station may be continued without disturbing this wheel. In order that the wheel may be locked in an accurate position, the arm 36 is permitted by the spring 37 engaging a slot therein to yield just enough to permit the noses or catches upon the arms 36 and 29 to pass each other, such a yielding action, however, not being sufficient to permit the locked wheel to be advanced while the magnet 31 is operated as the other wheel or wheels 24 on the line are being moved. The wheel 24 is released by the magnet 38, whose armature has link connection with the dogs 34 27. The armature of the magnet 31 preferably has its armature in the form of a switch, this armature being a part of the conductor portion 15 and serving as a link when unattracted to connect the portions 15 15. A switch element 39 is also carried by the armature, but is insulated therefrom. This switch element forms a separable link when the armature is unattracted to connect the conductor portions 16 16, it being desirable to separate the said conductor portions at this point to overcome certain objections that might arise in practice. The armature of the magnet 31 when attracted engages an alternate contact that constitutes a local terminal of the electromagnet 38. The magnets 31, 35, and 38 are all desirably polarized. Each magnet includes two core elements whose free poles have induced therein by the permanent magnet associated therewith in accordance with well-known practice polar regions of the same sign. The windings about the magnets are so disposed as to create or tend to create poles or magnetic regions of unlike sign. The armatures of the magnets are desirably pivoted between the magnet-poles and are provided with retractile springs, holding the same in normal position against back stops. These armatures are polarized so that when the magnet-windings are out of circuit the actions upon the armatures are balanced, the retractile springs then serving to position the armatures. Obviously current may be passed through each magnet in such a direction as to secure a strong attraction at the pole farthest removed from the armature and a weakening of the pole nearest the armature, so that the armature may be operated. A reversal of such current obviously would not cause an actuation of the armature from normal. The windings of the magnets 31 and 35 are in series. The winding of one magnet, therefore, should be reversed with respect to the winding of the other, so that current of one polarity will eflect the operation of one magnet only and current of the opposite polarity will effect the operation of the other magnet only.

1 will now describe one form of switching apparatus at the exchange employed for controlling the operation of the electromagnets at the substations. The battery is employed for the purpose of this control. It may be understood for the purpose of illus tration that the magnet 31 will respond only when the positive side of the battery 40 is connected with the sleeve side of the line and the negative side with the tip side of the line for the purpose of setting the switch. The locking-magnet, on the other hand, will then have to respond to a reverse direction of the battery-that is, where the negative pole of the battery is connected with the sleeve side and the positive pole of the battery with the tip side. To bring about this control of the battery, I provide a set or selecting key 41, whose alternate contact 42 is connected with the negative pole of the battery and whose alternate contact 43 is connected with the positive pole of the battery. When the actuatinglever 44 thrusts the springs of the key 41 into engagement with their alternate contacts, the negative pole of the battery may be traced to connection with the alternate contact 45 of the key 8, while the positive pole of the battery may have its connection traced to the alternate contact 46. The lever of key 41 is locked to separate the springs of said key into engagement with their alternate contacts, whereupon the lever 8 may be repeatedly actuated to bring the springs of key 8 into connection with their alternate contacts 45 and 46, whereby the battery 40 may be intermittently connectedin bridge, with its positive pole connected with the sleeve side of the line and its negative pole with the tip side of the line. Each movement of the lever 9 will cause an operation of the magnet 31 to set the wheel 24. When the wheel 24 has been properly set, it is locked by reversing the lever 44 to bring .the springs of the locking-key 47 into engagement with their alternate contacts, whereby the negative pole of the battery 40 is now connected with the alternate contact 46 and the positive pole of the battery is connected with the alternate contact 45, whereupon the battery 40 is connected between the sides of the circuit reversely to its previous connection, whereupon said magnet locks the wheel 24, as before described. It is to be understood that the arms 29 are located at different places at the different stations with respect to the Wheel 24. In setting the wheel 24 the current is caused to pass through the polarized magnet 48 to actuate the supervisory indicator 49, that may be of any suitable form,

' the form illustrated emplpyinga hole 50 in the I ratchet 51, behind which wheel is located a stationary target for indicating therein the numbers of the different stations, the ratchet 51 having its opening 50 placed in front of the number corresponding to the number of impulses that are passed over the line in setting the wheels 24, so that the operator after having set one wheel may readily determine how many more impulses are necessary to set the other wheel. When the operator desires to restore a subscribers station or stations to normal condition, she depresses the plunger 52, thereby again connecting the positive pole of the battery 40 with the sleeve side of the line and the negative pole of the battery with the tip side of the line, as will be readily understood by reference to the drawing, to effect an operation of the magnet 31, which connects the armature of the magnet 31 with the local free'terminal 52 of the grounded magnet 38. The tip side of the line is at the same time grounded with the aid of the grounded alternate contact-anvil 53' at the release-key 52, so that the magnet 38 is'operated to elevate the dogs 27 and 34 from the wheel 24 to permit said wheel to rotate to the normal position indicated, similar operation being effected at other stations. The electromagnet 54 at the exchange is also operated to lift the dogs 55 and 56 to permit the supervisory indicator 51 to be restored to its initial position.

()ne of the great ad vantages gained by means of my invention is such an organization of the apparatus that it may be applied to circuits previously equipped. To this end, as indicated, two parallel branches extend from the party-line to each telephone-station, one side having normal connection with the tele phone and the other with the switch-hook thereat.

It is obvious that changes may readily be made in the embodiment of my invention herein shown and particularly described without departing from the spirit of the invention, and I do not, therefore, desire to be limited to the precise construction and arrangement herein set forth; but,

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is

1. The combination with a party telephoneline having parallel branches extending therefrom to the telephone-receivers and switchhoolzs, one having normal connection with the telephone-receiver and the other with the switch-hook, of switching mechanism at each of the subscribers stations controlling the connection of said branches with the party- .line. electromagnetic mechanism in associatelephone-receiver and the other with the.

switch-hook, of switching mechanism at each of the subscribers stations controlling the connection of said branches with the party-line, electromagnetic mechanism in association with and provided for. effecting the operation of each switching mechanism, said electromagnetic mechanism and switching mechanism being in connection with said branches between said switch-hooks and telephone-re ceivers and the party-line,and switching mechanism at the exchange connected with the party-line for governing said electromagnetic mechanism, substantially as described.

3. The combination with a party telephoneline having parallel branches extending therefrom to the telephone receivers and switchhooks, one having normal connection with said telephone receiver and the other with the switch-hook, of switching mechanism at each of the subscribers stations controlling the connection of said branches with the party-line and governing the signal-receiving circuit thereat, electromagnetic mechanism in association with and provided for efiecting the operation of each switching mechanism, said electromagnetic mechanism and switching mechanism being in connection with said branches between said switch-hooks and telephone-recei vers and the party-line,and switching mechanism connected with the party-line for governing said electromagnetic mechanism, substantially as described.

V a. The combination with a party telephonelinehaving parallel branches extending therefrom to the telephonereceivers and switchhooks,one having normal connection with said telephonereceiver and the other with the switch-hook, of switching mechanism at each of the subscribers stations controlling the connection of said branches with the party-line and governing the signal receiving circuit thereat, electromagnetic mechanism in association with and provided for effecting the operation of each switching mechanism,said electromagnetic mechanism and switching mechanism being in connection with said branches between said switch-hooks and telephone-receivers and the party-line,and switching mechanism at the exchange connected with the party-line for governing sai'd electromagnetic mechanism, substantially as described.

5. The combination with a party telephoneline, of step-by-step switching mechanism at each of the subscribers stations on said line controllingthe association of the signal-receiving circuit thereat with the telephone-line, the said switching mechanisms at the different subscribers stations requiring difiering numbers of movements to elfect the control of the association of the signal-receiving circuits thereat with the telephone-line, electromagnetic mechanism inv association with and provided for el'lecting the stepby-step operation of the switching mechanism and to lock said step-bystep mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the properly-set mechanism, and switching mechanism connected with the party-line for governingsaid electromagnetic mechanisms, substantially as described.

6. The combination with a telephone-line extending from a plurality of subscribers stations to an exchange,of step-by-ste p switching mechanism at each of the subscribers stations on said line controlling the association of the signal-receiving circuit thereat with the telephone-line, the said switching mechanisms at the different subscribers stations requiring differing numbers of movements to effect the control of the association of the signal-receiving circuits thereat with the telephone-line, electromagnetic mechanism in association with and provided for eifecting the step-by-step operation of the switching mechanism and to lock said step-by-step mechanism when properly placed, whereby the movement ot'switching mechanism at another station may be continued without affecting the properly set mechanism, and switching mechanism at the exchange governing the operation of the aforesaid electromagnetic mechanisms at the subscribers stations, substantially as described.

7. The combination with a party telephoneline, of step-by-step switching mechanism at each of the subscribers stations on said line controlling the association of the telephoneeircuit and signal-receiving circuit thereatwith the telephone-line, the said switching mechanisms at the difi'erent subscribers stations requiring differing numbers of movements to effect the control of the association of the telephone and signal-receiving circuits thereat with the telephone-line, electromage netic mechanism in association with and provided for effecting the step-by-step operation of the switching mechanism and to lock said step by step mechanism when properly placed, whereby the movement of Switching mechanism at another station may be continued without affecting the properly set mechanism, and switching mechanism connected with the party-line for governing said electromagnetic mechanisms, substantially as described.

8. The combination with a telephone-line extending from a plurality of subscribers stations to an exchange, of step-by-step switching mechanism at each of the subscribers stations on said line controlling the association of the telephone-circuit and signal-receiving circuit thereat with the telephone-line, the said switching mechanisms at the different subscribers stations requiring differing numbers of movements to effect the-control of' the association of' the telephone and signal-receiving circuits thereat with the telephone-line, electromagnetic mechanism in association with and provided for effecting the step-by-step operation of the switching mechanism and to lock said step-by-step mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the properly set mechanism, and switching mechanism at the exchange governing the operation of the aforesaid electromagnetic mechanisms at the subscribers stations, substantially as described.

9. The combination with a party telephoneline, of selective switching mechanism at the subscribers stations thereon, electromagnetic mechanism at each of' the stationsfor selectively operating said switching mechanism thereat and operativelyconnected to the telephone line and signal current generating mechanism at each subscribers station, whereby the subscribers may initiate calls, the selective switching mechanisms at the different subscribers stations serving when in normal conditions of use to close the signal-receiving circuits at the subscribers stations, whereby the subscribers may directly signal each other without theaid of' the operator, substantially as described.

10. The combination with a party telephoneline, of step-by-step switching mechanism at each of the subscribers stations on said line controlling the association of' the signal-receiving circuit thereat with the telephone-line, the said switching mechanisms at the different subscribers stations requiring differing numbers of movements to effect the control of' the association of the signal-receiving circuits there at with the telephone-line, electromagnetic mechanism in association with and provided for effecting the step-by-step operation of the switching mechanism and to lock said mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the properly-set mechanism, said switching mechanism each including two electrically-connected elements and a rider normally in connection with one element and adapted to be brought into connection with the other element by the electromagnetic mechanism, the subscribers circuit including the rider and the element engaging the same, said elements at the different stations being spaced varying distances apart, said elements being insulated from the rider save when in direct contact therewith, and switching mechanism connected with the party-line for governing said electromagnetic mechanisms, substantially as described.

11. The combination with a telephone-line extending from a plurality of subscribers stations to an exchange, of' step-by-step switching mechanism at each of' the subscribers stations on said line controlling the association of' the signal-receiving circuit thereat with the telephone-line, the said switching mechanisms at the different subscribers stations requiring differing numbersof movements to effect the control of the association of the signal-receiv ing circuits thereat with the telephone-line, electromagnetic mechanism in association with and provided for effecting the step-by-step operation of' the switching mechanism and to lock said mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the properly-set mechanism, said switching mechanism each including two electrically-connected elements and a rider normally in connection with one element and adapted to be brought into connection with the other element by the electromagnetic mechanism, the subscribers circuit including the rider and the element engaging the same, said elements at the different stations being spaced varying distances apart, said elements being insulated from the rider save when in direct contact therewith, and switching mechanism at the exchange governing the operation of the aforesaid electromagnetic mechanisms at the subscribers stations, substantially as described- 12. The combination with a party telephoneline, of step-by-step switching mechanism at each of' the subscribers stations on said line controlling the association of the telephonecircuit and signal-receiving circuit thereat with the telephone-line, the said switching mechanisms at the different subscribers stations requiring differing numbers of' movements to effect the control of" the association of the telephone and signal-receiving circuitsthereat with the telephone-line, electromagnetic mechanism in association with and provided for effecting the step-by-step operation of the switching mechanism and to lock said mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the properly-set mechanism, said switching mechanism each including two electricallyconnected elements and a rider normally in connection with one element and adapted to be brought into connection with the other element by the electromagnetic mechanism, the subscribers circuit including the rider and the element engaging the same, said elements at the different stations being spaced varying distances apart, said elements being insulated from the rider save when in direct contact therewith, and switching mechanism connected with the party-line for governing said electromagnetic mechanisms, substantially as described.

13. The combination with a telephone-line extending from a plurality of subscribers stations to an exchange, of step-by-step switching mechanism at each of the subscribers stations on said line controlling the association of the telephone-circuit and signal-receiving circuit thereat with the telephone-line, the said switching mechanisms at the different subscribers stations requiring differing numbers of movements to effect the control of the association of the telephone and signal-receiving circuits thereat with the telephone-line, electromagnetic mechanism in association with and provided for effecting the step-by-step operation of the switching mechanism and to lock said mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the properly-set mechanism, said switching mechanism each including two electrically-connected elements and a rider normally in connection with one element and adapted to be brought into connection with the other element by the electromagnetic mechanism, the subscribers circuit including the rider and the element engaging the same, said elements at the different stations being spaced varying distances apart, said elements being insulated from the rider save whenin direct contact therewith, and switching mechanism at the exchange governing the operation of the aforesaid electromagnetic mechanisms at the subscribers stations, substantially as described.

14. The combination with a party telephoneline, of selective switchingmechanism at the subscribers station's thereon, electromagnetic mechanism at each of the stations for selec tively operating said switching mechanism thereat and operatively connected with the telephone-line, said switching mechanism each including two electrically-connected elements and a rider normally in connection with one element and adapted to be brought into connectionwith the other element by the electromagnetic mechanism, the subscribers circuit including the rider and the element engaging the same, said elements at the different stations being spaced varying distances apart, said elements being insulated from the rider save when in direct contact therewith, and signal-current-generating mechanism at each subscribers station, whereby the subscribers may initiate calls, the selective switchingmechanisms at the different subscribers stations serving when in normal conditions of use to close the signal-receiving circuits at the subscribers stations whereby the subscribers may directly signal each other without the aid of the operator, substantially as described.

15. The combination with aparty telephoneline, of step-by-step switching mechanism at each of the subscribers stations on said line controlling the association of the signal-rcceiving circuitthereat with the telephone-line, the said switching mechanisms at the different subscribers stations requiring differing numbers of movements to effect the control of the association of the signal-receiving circuits thereat with the telephone-line, electromagnetic mechanism in association with and provided for effecting the step-by-step operation of the switching mechanism and to lock said step-by-step mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the properly-set mechanism, said electromagnetic mechanism being in operative connection with the partyline, and switching mechanism connected with the party-line for governing said electromagnetic mechanisms, substantially as described.

16. The combination with a telephone-line extending from a plurality of subscribers stations to an exchange, of step-by-step switch ing mechanism at each of' the subscribers stations on said line controlling the association of the signal-receiving circuit thereat with the telephone-line, the said switching mechanisms at the different subscribers stations requiring differing numbers of' movements to effect the control of the association of' the signal-receiving circuits thereat with the telephone-line, electromagnetic mechanism in association with and provided for effecting the step-by-step operation of the switching mechanism and to lock said step-by-step mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the properly-set mechanism, said electromagnetic mechanism being in operative connection with the party-line, and switching mechanism at the exchange governing the operation of the aforesaid electromagnetic mechanisms at the subscribers stations, substantially as described.

17. The combination with a party telephoneline, of step-by-step switching mechanism at each of the subscribers stations on said line controlling the association of the telephonecircuit and signal receiving circuit thereat with the telephone-line, the said switching mechanisms at the different subscribers stations requiring differing numbers of movements to effect the control of the association of' the switching mechanism and to lock said step-by-step mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the properly-set mechanism, said electromagnetic mechanism being in operative connection with the party-line, and switching mechanism connected with the party-line for governing said electromagnetic mechanisms, substantially as described.

18. The combination'with a telephone-line extending from a plurality of subscribers stations to an exchange, of step-by-step switching mechanism at each of the subscribers stations on said line controlling the association of the telephone-circuit and signal-receiving circuit thereat with the telephone-line, the said switching mechanisms at the different subscribers stations requiring differing numbers of' movements to effect the control of the association of the telephone and signal-receiving circuits thereat with the telephone-line, electromagnetic mechanism in association with and provided for effecting the step-by-step operation of' the switching mechanism and to lock said step-by-step mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the properly-set mechanism, said electromagnetic mechanism being in operative connection with the partyline, and switching mechanism at the exchange governing the operation of the aforesaid electromagnetic mechanisms at the subscribers stations, substantially as described.

19. The combination with a party telephoneline, of step-by-step switching mechanism at each of the subscribers stations on said line controlling the association of the signal-receiving circuit thereat with the telephoneline, the said switching mechanisms at the different subscribers stations requiring differing numbers of' movements to effect the control of the association of the signal-receiving circuits thereat with the telephone-line, electromagnetic mechanism in association with and provided for effecting the step-by-step operation of the switching mechanism and to lock said mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the proper] y-set mechanism, said electromagnetic mechanism being in operative connection with the party-line, said switching mechanism each including two electricallyconnected elements and a rider normally in connection with one element and adapted to be brought into connection with the other element by the electromagnetic mechanism, the subscribers circuit including the rider and'the element engaging the same, said elements at the different stations being spaced tions to an exchange, of step-by-step switching mechanism at each of the subscribers stations on said line controlling the association of the signal-receiving circuit thereat with the telephone-line, the said switching mechanisms at the different subscribers stations requiring differing numbers of movements to effect the control of the association of the signal-receiving circuits thereat with the telephone-line, electromagnetic mechanism in association with and provided for effecting the step-by-step operation of the switching mechanism and to lock said mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the properly-set mechanism, said electromagnetic mechanism being in operative connection with the party-line, said switching mechanisms each including two electrically connected elements and a rider normally in connection with one element and adapted to be brought into connection with the other element by the electromagnetic mechanism, the subscribers circuit including the rider and the element engaging the same, said elements at the different stations being spaced varying distances apart, said elements being insulated from the rider save when in direct contact therewith. and switching mechanism at the exchange governing the operation of the aforesaid electromagnetic mechanisms at the subscribers stations, substantially as described.

21. The combination with a party telephoneline, of step-by-step switching mechanism at each of the subscribers stations, on said line controlling the association of the telephonecircuit and signalreceiving circuit thereat with the telephone-line, the said switching mechanisms at the different subscribers stations requiring differing numbers of movements to effect the control of the association of' the telephone and signal-receiving circuits thereat with the telephone-line, electromag-' netic mechanism in association with and provided for effecting the step-by-step operation of the switching mechanism and to lock said mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the properly-set mechanism, said electromagnetic mechanism being in operative connection with the party-line, said switching mechanism each including two electricallyconnected elements and a rider normally in connection with one element and adapted to be brought into connection with the other element by the electromagnetic mechanism,

the subscribers circuit including the rider and the element engaging the same, said elements at the different stations being spac'ed varying distances apart, said elements being insulated from the rider save when in direct contact therewith, and switching mechanism connected with the party-line for governing said electromagnetic mechanisms, substantially as described.

22. The combination with a telephone-line extending from a plurality of subscribers stations to an exchange, of step-by-step switching mechanism at each of the subscribers stations on said line controlling the association of the telephone-circuit and signal-receiving circuit thereat with the telephone-line, the

said switching mechanisms at the different,

subscribers stations requiring diflering numbers of movements to effect the control of the association of the telephone and signal-receiving circuits thereat with the telephone-line, electromagnetic mechanism in association with and provided for efi'ecting the step-by-step operation of the switching mechanism and to lock said mechanism when properly placed, whereby the movement of switching mechanism at another station may be continued without affecting the properly-set mechanism, said electromagnetic mechanism being in operative connection with the party-line, said switching mechanisms each including two electricallyconnected elements and a rider normally in connection with one element and adapted to be brought into connection with the other element by the electromagnetic mechanism, the subscribers circuit including the rider and the element engaging the same, said elements at the different stations being spaced varying distances apart, said elements being insulated from the rider save when in direct contact therewith, and switching mechanism at the exchange governing the operation of the afore said electromagnetic mechanisms at the subscribers stations, substantially as described.

23. The combination with a party telephoneline, of selective switching mechanism at the subscribers stations thereon, electromagnetic mechanism at each of the stations operatively connected with the telephone-line for selectively operating said switching mechanism thereat, said electromagnetic mechanism being in operative connection with the partyline, said switching mechanism each including two electrically-connected elements and a rider normally in connection with one element and adapted to be brought into connection with the other element by the electromagnetic mechanism, the subscribers circuit including the rider and the element engaging the same, said elements at the different stations being spaced varying distances apart, said elements being insulated from the rider save when in direct contact therewith, and signal-currentgenerating mechanism at each subscribers station, whereby the subscribers may initiate calls, the selective switching mechanisms at the different subscribers stations serving when in normal conditions of use to close the signalreceiving circuits at the subscribersstations whereby the subscribers may directly signal each other without the aid of the operator, substantially as described.

In testimony whereof I hereunto ailixed my signature in presence of two witnesses.

EDWARD A. BUELL.

l/Vitnesses:

Boer. H. PURKINSON, CHARLES L. HINE. 

